Hydraulic press circuit having intensifier utilized to decrease pressure and increase volume or vice versa



Sept. 18, 1951 w. R. TUCKER HYDRAULIC PRESS CIRCUIT HAVING INTENSIFIER UTILIZED TQ DECREASE PRESSURE AND INCREASE VOLUME OR VICE VERSA 3 Sheets-Sheet 1 Filed Nov. 26, 1945 WARREN RJ'UCKERI SIFIER UTILIZE ME OR VICE VER 3 Sheets-Sheet 2 R CIRCUIT HAVING INTEN URE AND INCREASE VOLU W. R. TUCKE Sept. 18, 1951 HYDRAULIC PRESS DECREASE PRESS Filed NOV. 26, 1945 Arrow W. R. TUCKER Sept. 18, 1951 HYDRAULIC PRESS CIRCUIT HAVING INTENSIFIER UTILIZED TO DECREASE PRESSURE AND INCREASE VOLUME OR VICE VERSA Filed NOV. 26, 1945 3 Sheets-Sheet 5 IHVENTOR MH IM WARREN R.7'UCKER,

Patented Sept. 18, 1951 HYDRAULIC mass cmcurr mi VING IN- TENSIFIER UTILIZED TO DECREASE PRES- SURE AND INCREASE VOLUDIE OB VICE VERSA Warren It. Tucker, Dayton, Ohio, assignor to H-P-M Development Corporation, Wilmington,

DeL, a corporation of Delaware Application November 26, 1945, Serial No. 830,748

(Cl. 6H2) 1 Claim.

This invention relates to fluid operable apparatus and particularly to fluid operable press operating circuits which include a pressure converter.

The primary object of this invention is to provide an operating circuit for a hydraulic press in which a plurality of operating speeds and working pressures may be obtained from a single fluid source in connection with a pressure converter.

Another object is to provide an operating circuit for a hydraulic press in which the ram may be advanced at high speed to engage the work, thereafter proceed at working speed into the work, thereafter advance still further into the work or dwell on the work at still higher pressures, and to accomplish this without the use of booster rams or surge valves.

It is still another object to provide an operating circuit for a hydraulic press wherein extremely high closing speeds and high working pressures may be had with a simple and relatively small ram without the use of booster rams, surge valves or similar auxiliaries.

These and other objects and advantages become more apparent upon reference to the following specification taken together with the accompanying drawings in which:

Figure l is a diagrammatic view of a circuit utilizing a pressure converter as an intensifier;

Figure 2 is a view similar to Figure 1 but showing the converter utilized as a pressure reducer;

Figure 3 is a vertical section through a typical converter and is indicated by a line 33 on Figure 4;

Figure 4 is a transverse vertical section through the converter and is indicated by the line l--l on Figure 3;

Figures 5, 6, 7 and 8 are transverse sections through the converter and are indicated respectively by the lines -5, 6-45, 'II, and lt on Figure 3;

Figure 9 is a diagrammatic view of a press circuit utilizing a pressure converter according to this invention;

Figure 10 is a view of a modified valve structure adapted for being used in connection with the circuit of Figure 9;

Figure 11 is a partial circuit illustrating automatic control means for shifting the valves; in the circuits of Figures 9 and 10;

Figure 12 is an electrical diagram for use in connection with the control circuit of Figure 11; and

and the manner of associating with it the several control switches of the circuit of Figure 12.

General arrangement According to this invention the discharge of fluid from a source is divided into increments of volume in the pressure and flow converter, the increments are modified in quantity through a connection with exhaust. and the modified increments are then discharged to a motor or similar hydraulic auxiliary.

If the volume of the increments are reduced by exhausting a portion thereof to exhaust, the energy of the exhausted portion is utilized in compressing the remainder to a higher pressure so that the product of volume and pressure at the inlet of the converter is substantially equal to the production of volume and pressure at the outlet.

If the increments are increased by the connection with the exhaust, then the fluid which is discharged from the converter is at a lower pressure and at a correspondingly greater volume.

Referring to Figure l, for purposes of explanation there is ditically illustrated the action of a single piston-cylinder unit, the pressure converter when it is utilized for intensitfying pressure and which, as hereinafter described, comprises a plurality of such units which are alternately controlled by a common valve means. In this figure a pump Ill draws fluid from a reservoir l2 through a conduit ll and discharges fluid under pressure into a conduit l6. Thev flow in the conduit i8 is divided by a valve member, not shown in Figs. 1 and 2, in the branch conduits l6 and I6" which communicate, respectively, with the chambers 18 and 20 of the single pistoncylinder unit generally indicated at 22.

This unit of the pressure converter comprises a cylinder 24 which has a central portion within which is reciprocable the piston 28 and the reduced diameter end portions within which are reciprocable the pistons 28 and 30. The piston 2t reciprocates in the chamber it while the piston 30 reciprocates in the opposite end chamber indicated at 32. The piston 26 divides the central portion of the cylinder 24 into the opposite end chambers 20 and 34.

The chamber 34 is connected by a conduit 38 with the reservoir it while the chamber 32 is connected by a conduit 38 with the inlet of a motor 40. The other side of the motor All my be connected by a conduit 42 with the reservoir II for returning exhaust fluid thereto.

Figure 13 is a view of the motor of Figure 9 I As illustrated Figure 1, the pump is supplying fluid to both of the upper working areas of the pistons 28 and 28 while the lower workin areas are connected one with the motor inlet and the other with exhaust. Thus, the pressure delivered to the motor 40 is augmented over the pressure delivered by the pump by the ratio of the said upper areas to the area which is connected to the motor inlet. By apportioning the sizes of the pistons, any desired intensification of pressure may be had.

Figure 2 is a similar diagrammatic illustration of a single cylinder-piston unit wherein the circuit is modified to utilize the unit 22' as a pressure reducing, and a flow augmenting device. In this view, the discharge conduit it of the pump I is connected to the chamber l8, the chamber 20 is connected by a conduit. with the reservoir l2, the chamber 82 is connected by a conduit 88 with the inlet of the motor III and the chamber 84 is connected by a conduit 88 with the conduit l8.

In Figure 2, the pressure supplied to the motor is decreased below that supplied by the pump by the ratio of the two lower working areas to the area supplied by the pump. As in the case of the system shown in Figure 1, only one of a plurality of cylinder-piston units is disclosed for sake of clarity, it being understood that the complete converter. as will hereinafter be described, comprises a plurality of these piston-cylinder units and a valve means operable continuously to alternate the flow of fluid from one end of the cylinders to the other to reciprocate the pistons so that a continuous flow of fluid results.

In Figure 1, it will be noted that a portion of the fluid previously supplied by the pump to one of the lower areas of the piston is discharged to exhaust, and that the energy thereof was utilized for pressurizing fluid previously supplied by the pump to the chamber l8. It will be noted in connection with Figure 2 that the supply of fluid from the pump to the converter is being augmented by a further supply from the exhaust and that a portion of the energy in the fluid from the pump is utilized to compress the fluid so supplied from exhaust on the previous piston stroke to a higher pressure.

Pressure and flow converter The fiuid-pressure-volume converter or fluid intensifier 22 is more particularly shown in Figures 3 through 8 and is fully shown and described in my United States Patent Number 2,486,079, issued October 25, 1949, entitled Hydraulic Booster."

The fluid-pressure-volume converter comprises a cylinder block III which has a plurality of axial bores 52 circumferentially spaced about a central bore ll. The bores 52 provide cylinders within which reciprocate the pistons 58 havin the oppositely extending reduced piston portions 8 attached thereto. The portions 58 reciprocate in bored cylindrical plugs I which are inserted from opposite ends of the block 58 into somewhat enlarged end ortions of the bores 52. The piston 58 and the rods 58 deflne the upper working areas indicated at A and B and the lower working areas indicated at C and D. The working areas are connected by radial passages with the central bore ll of the block "at different levels.

Within the bore 54 is mounted a valve member indicated at 62 which is supported on the antifriction bearings Bl andwhich has an operating shaft 80 whereby the valve member may be rotated. The block II has port 68 (Figure 4) and.

the valve member 82 has a groove III at the level of the said port. The groove I! is communicated with the levels of the connections to the areas A and B by a pair of oppositely disposed notches I2 which extend somewhat less than 90 about the periphery oi. the said valve member. The levels of the connections to the areas 0 and D are com-.- municated with the groove III by a pair of oppositely disposed notches I4 which are similar to the notches I2 but which are disposed at 90 therefrom.

The valve member comprises the groove It at the upper end thereof and the groove I8 at the lower end thereof which communicate by a bore with port 82 in the block II. The groove 16 communicates with the level of the connection with the area A by means of the oppositely disposed notches 84 which are disposed at from the notches I2 so that alternate communication may be had with the area A. The groove I8 is similarly provided with the notches 8B which are disposed at 90 from the notches 84.

Arranged at the level of the connection with the area B are the oppositely disposed flats or notches 88 which are disposed at 90 from the notches 12 so that the said notches will alternately communicate with the area B. The

notches 88 are connected by radial bores with thecentral passage 80 in the valve member which communicates directly with an exhaust conduit 82. At the level of the connection with the area C are similarly arranged notches 84 which communicate with the central passage 80 and which are disposed at 90 from the notches 88.

It will be apparent that the rotation of the valve member 62 is effective first to connect the port 68 to the areas 0 and D while connecting area B to the exhaust 82 and the area A to the port 82 and thereafter to reverse the said connections; that is to connect A and B to the port 68, C to exhaust and D to the port 82. It will also be apparent that by providing a plurality of cylinders and pistons, the same will operate to receive and to discharge fluid in overlapping increments so that substantially continuous operation may be had. a

By connecting the pump to the port 68, the converter 22 acts as a pressure intensifier, and by connecting the pump the port 82, the converter acts as a pressure reducer. In either case, the efiiciency of conversion is high and the energy of the working fluid, represented by the production of pressure and volume, is substantially the same at the inlet and outlet ports of the converter,

Operating circuit of Figure 9 In Figure 9, there is illustrated an upward acting ram Illll having an advancing means I02; a retracting means I and reciprocably mounted in a cylinder I08. The advancing and retracting means are connected with the service ports of the four-way reversing valve I" which receives fluid from a conduit I I0 and which has an exhaust connection I I2. I

The conduit H0 is connected with one of the ports of a four-way distributing valve Ill which also has connected therewith the conduits 11$, 8, and I20. The conduit II! is connected with the discharge side of a pump I22 which draws fluid from a reservoir through a conduit I24. The conduit I I8 connects with the port 68 of the converter 22 and the conduit I20 connects with the port 82. I

The distributing valve Ill includes the valve member I28 movable to connect the conduits [It and H8 and the conduits III and III or, to connect the conduits H and I20, and the conduits H0 and H0. In the first position, the converter acts as a pressure reducer and delivers an augmented quantity of fluid to the conduit H0 and, in the second case the converter acts as a pressure intensifier and delivers a reduced volunie of fluid at intensified pressures to the conduit H0.

For rotating the valve member 02 of the converter 22, there is provided the electric motor I28 which is connected with the shaft 00 and which operates continuously to rotate the valve member for eflecting the aforementioned connections to the reciprocating pistons in the converter.

In Figure 10, there is illustrated a valve which provides for a third pressure for actuating the motor by the passage I30 which is operable directly to connect the conduits H8 and H0 when the valve member is in a predetermined position. By means of the valve passage shown in Figure 10, there is available for actuating the motor a low pressure large volume fiow when the converter is connected as a pressure reducer, a medium volume medium pressure fiow when the pump is directly connected with the passage I30, and a low volume high pressure fiow when the converter is connected to act as a pressure intensifier. The ram I00 may thus be advanced at high speeds, perform work at medium working speeds and finally dwell or do further work at intensified pressure.

Control circuit of Figures 11 and 12 For obtaining an automatic cycle of operations of the work ram I00, there may be provided the circuit shown in Figure 11 which is controlled by the electrical circuit oi. Figure 12.

In Figure 11, the conduit IIB from the pump is connected with the inlet port 200 of a valve 202 which has a rotatable valve member 204. As the valve member 204 rotates counterclockwise, communication is successively established between the pressure port 200 and the conduits I20, H0, and I I8. The valve member 204 comprises the notches 205 and 200, the first or which connects the conduits H0 and H0 when the port 200 is in communication with the conduit I20, and the second of which connects the conduits H0 and I20 when the port 200 is in communication with the conduit H0.

In Figure 11, the four-way valve I08 is continuously urged by a spring 2] 0 into position to connect conduit II 0 with the ram retracting means and is adapted for being moved into position to connect the conduit IIO with the ram advancing means by the energization of the solenoid SI.

For shifting the valve member 204 into its several positions, there is provided a ratchet wheel 2I2 which has teeth that may be engaged by a pawl 2" when the latter is moved leftwardly by energization of a solenoid S2. The ratchet wheel and, therefore, the valve member 204 are continuously urged clockwise by a torsion spring 2I8 and are retained in any of their operative positions by a latch bolt H0. The latch bolt may be withdrawn at any time by the energization of a solenoid S3 so that the torsion spring 2l0 may return the valve member to its Figure 11 position.

For controlling the actuation of the solenoids SI, S2 and 83, the circuit of Figure 12 is provided. In Figure 12, there is connected between t power u LI and contactor n A II or relatively small size. This eliminates the cost in series with the normally closed contactor blades B2. and the normall open starting switch 220. The starting switch is bypassed by the normally open blades AI of the contactor A and the normally open limit switch LSI. The blades AI provide a holding circuit for maintaining the contactor A energized, and the limit switch LSI is located to be closed by the ram I00, as shown in Figure 13, in its fully retracted position for giving a full automatic cycle when desired.

Also connected between LI and L2 is the solenoid SI in series with the normally open blades A2. The energization 01' A will close the blades A2 and energize SI to shift the valve I00 to direct actuating fiuid to the ram advancing means. At this time the valve member 204 occupies its Figure 11 position and the ram I00 advances at a rapid rate and under low pressure.

When the ram has advanced a predetermined amount, it may engage and temporarily close a limit switch LS2 which will energize S2 to aotuate the pawl 2I4 to advance the ratchet wheel 2 I2 and the valve member 204 to their next position. This connects the pump directly with the ram advancing means and the speed of the ram is reduced and the operating pressure available is correspondingly increased. Optionally, there may be provided a pressure switch connected with the advancing means and indicated at TI which is temporarily closed in response to a predetermined pressure acting on the ram for energizing the solenoid $2.

In response to a further advance of the ram I00, the solenoid S2 is energized again to index the valve member 204 to its third position by the temporary closure of a limit switch LS8. There may also be operated the pressure switch T2 which is temporarily closed in response to a higher pressure than the pressure which actuates TI for energizing S2. The ram I00 now advances at a still lower speed with a still higher working pressure available.

In order to halt the working stroke of the ram I00, there is provided a limit switch LS4 which is closed when the ram has advanced a predetermined amount and energizes a contactor coil .3. O tionally, the coil B may be energized by the closure of a pressure switch T8 connected with the ram advancing means. Energization of B closes the blades BI thereof and energizes the solenoid S3 to withdraw the latch bolt 2I0 from engagement with the ratchet wheel 2 I2 to permit the torsion spring 2l6 to return the valve mealher 204 to its Figure 11 position. Simultaneously, the blades 132 open, denergize A and thus deenergize sI to permit the spring 2I0 to move the valve I00 into position to connect the conduit "0 with a ram retracting means. The ram is thus retracted at high speed to its Figure 9 position.

The general arrangement of the ram I00, the limit switches LSI. LS2, LS3. and LS4; and the pressure switches TI T2, and T3 is shown in Figure 13.

It will be apparent that the automatic control circuit of Figure 11 and the electrical diagram of Figure 12 will present only one of many combinations that may be had by employing the converter 22 for intensifying fluid pressures or for au menting fluid flows.

By utilizing the principles 0! this invention a hydraulic press may be constructed which has a rapid advancing speed, a first working speed and pressure, and a second working speed and pressure, all of which may be had with a simple ram oibooster rams, surge valves. permits the-ram to be made substantially smaller for any given working tonnage, and does so without sacriflcing ""e'fliciency or flexibility'oi the apparatus.

- ,It-wiil' be understood that this invention is susceptible to modification in order to adopt it to difl'erent usages and conditions and, accordingly,

it is desired to comprehend such modifications within this invention as may fall within the scope oi the appended claim.

'I claim:

In a hydraulic control. circuit; a differential fluid motor having oppositely disposed pressure areas; a reversing valve having a fluid inlet and 'an exhaust outlet and a pair oiservice ports connected respectively with the oppositely disposed pressure areas of said motor and operable selectively to direct fluid introduced within the fluid Tinlet to either of the pressure areas of said motor while connecting the oppositarea to exhaust; is fluid displacement pump; ailuid pressure-volume converter having flrst, second and exhaust ports and a rotary valve member; motor means .drivingly connected "with the 'valve member oi said converter {or rotating the latter, said converter being operable upon rotation 01' the valve --'member' and upon the introduction of pressure fluid into either the flrst or second port to discharge pressure fluid at a modifled pressure-voliime ratio from the opposite port; valve means having connections respectively with said pump,

the flrst and second ports of said converter and the inlet port oi said reversing valve and having a valve member therein movable to a flrst posi- 8 -tion connecting said pump with the flrst port oi said converter while connecting the second port of said converter with the inlet port 0! said reversing valve, and a second position connecting said pump with the second port of said converter while connecting the flrst port of'said converter with the inlet port of said reversing valve; and means responsive to fluid pressures within said fluid motor and connected withthe movable valve member or said valve means'jior moving the latter between said flrst and second positions.

WARREN R. TUCKER.

REFERENCES CITED The following references are ofrecord in the flle oi this patent:

UNITED STATES PATENTS 

